| Message ID | 1594368010-4419-5-git-send-email-amit.kachhap@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: add Armv8.3 pointer authentication enhancements | expand |
On Fri, Jul 10, 2020 at 01:30:10PM +0530, Amit Daniel Kachhap wrote: > The existing comment about steppable hint instruction is not complete > and only describes NOP instructions as steppable. As the function > aarch64_insn_is_steppable_hint allows all white-listed instruction > to be probed so the comment is updated to reflect this. > > Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> > --- > Changes since v3: > * New patch. > > arch/arm64/kernel/probes/decode-insn.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/kernel/probes/decode-insn.c b/arch/arm64/kernel/probes/decode-insn.c > index 263d5fba4c8a..3912a37cb117 100644 > --- a/arch/arm64/kernel/probes/decode-insn.c > +++ b/arch/arm64/kernel/probes/decode-insn.c > @@ -42,8 +42,10 @@ static bool __kprobes aarch64_insn_is_steppable(u32 insn) > != AARCH64_INSN_SPCLREG_DAIF; > > /* > - * The HINT instruction is is problematic when single-stepping, > - * except for the NOP case. > + * The HINT instruction is steppable only if it is in whitelist > + * and the rest of other such instructions are blocked for > + * single stepping as they may cause exception or other > + * unintended behaviour. > */ > if (aarch64_insn_is_hint(insn)) > return aarch64_insn_is_steppable_hint(insn); > -- > 2.17.1 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff --git a/arch/arm64/kernel/probes/decode-insn.c b/arch/arm64/kernel/probes/decode-insn.c index 263d5fba4c8a..3912a37cb117 100644 --- a/arch/arm64/kernel/probes/decode-insn.c +++ b/arch/arm64/kernel/probes/decode-insn.c @@ -42,8 +42,10 @@ static bool __kprobes aarch64_insn_is_steppable(u32 insn) != AARCH64_INSN_SPCLREG_DAIF; /* - * The HINT instruction is is problematic when single-stepping, - * except for the NOP case. + * The HINT instruction is steppable only if it is in whitelist + * and the rest of other such instructions are blocked for + * single stepping as they may cause exception or other + * unintended behaviour. */ if (aarch64_insn_is_hint(insn)) return aarch64_insn_is_steppable_hint(insn);
The existing comment about steppable hint instruction is not complete and only describes NOP instructions as steppable. As the function aarch64_insn_is_steppable_hint allows all white-listed instruction to be probed so the comment is updated to reflect this. Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> --- Changes since v3: * New patch. arch/arm64/kernel/probes/decode-insn.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)